A passing motorist used his cell phone camera to catch a Tesla Model X driver apparently sleeping at the wheel as the car cruises down the highway on Autopilot.

The footage was filmed on a highway outside Las Vegas by a Jalopnik reader who wished to remain anonymous, according to the automobile and driving website.

From the video, we cannot tell if the man's hand is resting on the wheel or if some device or other method is being used to circumvent Autopilot's safeguards, which normally would barrage him with increasingly aggressive warnings before flipping on hazard lights and slowing car until it stops.

While he looks to be napping, it's possible that he suffered a medical episode that rendered him unconscious. Of course, that does not explain why the Autopilot safety features did not kick in.

Tesla has repeatedly warned drivers in the past that despite its name, Autopilot is not an autonomous driving system, but rather a driver-assist feature. It requires an alert human to take control at all times.

"The feedback that we get from our customers shows that they have a very clear understanding of what Autopilot is, how to properly use it, and what features it consists of. When using Autopilot, drivers are continuously reminded of their responsibility to keep their hands on the wheel and maintain control of the vehicle at all times. This is designed to prevent driver misuse, and is among the strongest driver-misuse safeguards of any kind on the road today."

The driver in the video appears woefully unprepared to maintain control. We don't know what happened to him — hopefully he woke up in time to avoid a serious accident.